This disclosure relates to seals and more particularly, to reversible thermally expandable and/or contractible seal assemblies for sealing opposing surfaces.
Current methods and assemblies for sealing opposing surfaces such as doors and trunk lids, for example, include the use of flexible elastic membranes and structures that sealingly compress upon pressing contact of the opposing surfaces. Typical materials include various forms of elastomers, e.g., foams and solids, that are formed into structures having solid and/or hollow cross sectional structures. The geometries of the cross sections are varied and may range from circular forms to irregular forms having multiple slots and extending vanes.
Traditional passive door seal design as noted above must compromise between functional adequacy and user operation. Typically, improved sealing results from greater contact area and adequate pressure over the seal length. This approach generally requires an increasing degree of force to close the door as compared to less contact area and force. Additionally, manufacturing tolerances which vary over the width of the doors may require a greater seal compression over the length of the seal than is necessary to ensure that the point of the door located the furthest from the frame will have adequate sealing area and pressure to prevent moisture or noise from entering the vehicle. This may result in more total compression and force over the entire door than is necessary, thus increasing the door closure force. In addition, general manufacturing issues including interactions of various components involved in sealing technologies may result in increased manufacturing cycle time due to the necessity to redesign the seal to match vehicle conditions.
Another problem with current seals is the tradeoff in seal effectiveness. Seal effectiveness can generally be increased by increasing the interface pressure and/or area of the seal. In automotive applications, such as vehicle doors, the increased interface pressure and/or area of the seal results in increased door opening and closing efforts.
Accordingly, it is desirable to have active seal assemblies that can be controlled and remotely changed to alter the seal effectiveness, wherein the active seal assemblies actively change modulus properties. In this manner, in seal applications such as the vehicle door application noted above, door opening and closing efforts can be minimized yet seal effectiveness can be maximized.